| // Copyright (c) 2022 The Khronos Group Inc. |
| // Copyright (c) 2022 LunarG Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "source/opt/eliminate_dead_input_components_pass.h" |
| |
| #include <set> |
| #include <vector> |
| |
| #include "source/opt/instruction.h" |
| #include "source/opt/ir_builder.h" |
| #include "source/opt/ir_context.h" |
| #include "source/util/bit_vector.h" |
| |
| namespace { |
| |
| const uint32_t kAccessChainBaseInIdx = 0; |
| const uint32_t kAccessChainIndex0InIdx = 1; |
| const uint32_t kConstantValueInIdx = 0; |
| const uint32_t kVariableStorageClassInIdx = 0; |
| |
| } // namespace |
| |
| namespace spvtools { |
| namespace opt { |
| |
| Pass::Status EliminateDeadInputComponentsPass::Process() { |
| // Current functionality assumes shader capability |
| if (!context()->get_feature_mgr()->HasCapability(SpvCapabilityShader)) |
| return Status::SuccessWithoutChange; |
| analysis::DefUseManager* def_use_mgr = context()->get_def_use_mgr(); |
| analysis::TypeManager* type_mgr = context()->get_type_mgr(); |
| bool modified = false; |
| std::vector<std::pair<Instruction*, unsigned>> arrays_to_change; |
| for (auto& var : context()->types_values()) { |
| if (var.opcode() != SpvOpVariable) { |
| continue; |
| } |
| analysis::Type* var_type = type_mgr->GetType(var.type_id()); |
| analysis::Pointer* ptr_type = var_type->AsPointer(); |
| if (ptr_type == nullptr) { |
| continue; |
| } |
| if (ptr_type->storage_class() != SpvStorageClassInput) { |
| continue; |
| } |
| const analysis::Array* arr_type = ptr_type->pointee_type()->AsArray(); |
| if (arr_type != nullptr) { |
| unsigned arr_len_id = arr_type->LengthId(); |
| Instruction* arr_len_inst = def_use_mgr->GetDef(arr_len_id); |
| if (arr_len_inst->opcode() != SpvOpConstant) { |
| continue; |
| } |
| // SPIR-V requires array size is >= 1, so this works for signed or |
| // unsigned size |
| unsigned original_max = |
| arr_len_inst->GetSingleWordInOperand(kConstantValueInIdx) - 1; |
| unsigned max_idx = FindMaxIndex(var, original_max); |
| if (max_idx != original_max) { |
| ChangeArrayLength(var, max_idx + 1); |
| modified = true; |
| } |
| continue; |
| } |
| const analysis::Struct* struct_type = ptr_type->pointee_type()->AsStruct(); |
| if (struct_type == nullptr) continue; |
| const auto elt_types = struct_type->element_types(); |
| unsigned original_max = static_cast<unsigned>(elt_types.size()) - 1; |
| unsigned max_idx = FindMaxIndex(var, original_max); |
| if (max_idx != original_max) { |
| ChangeStructLength(var, max_idx + 1); |
| modified = true; |
| } |
| } |
| |
| return modified ? Status::SuccessWithChange : Status::SuccessWithoutChange; |
| } |
| |
| unsigned EliminateDeadInputComponentsPass::FindMaxIndex(Instruction& var, |
| unsigned original_max) { |
| unsigned max = 0; |
| bool seen_non_const_ac = false; |
| assert(var.opcode() == SpvOpVariable && "must be variable"); |
| context()->get_def_use_mgr()->WhileEachUser( |
| var.result_id(), [&max, &seen_non_const_ac, var, this](Instruction* use) { |
| auto use_opcode = use->opcode(); |
| if (use_opcode == SpvOpLoad || use_opcode == SpvOpCopyMemory || |
| use_opcode == SpvOpCopyMemorySized || |
| use_opcode == SpvOpCopyObject) { |
| seen_non_const_ac = true; |
| return false; |
| } |
| if (use->opcode() != SpvOpAccessChain && |
| use->opcode() != SpvOpInBoundsAccessChain) { |
| return true; |
| } |
| // OpAccessChain with no indices currently not optimized |
| if (use->NumInOperands() == 1) { |
| seen_non_const_ac = true; |
| return false; |
| } |
| unsigned base_id = use->GetSingleWordInOperand(kAccessChainBaseInIdx); |
| USE_ASSERT(base_id == var.result_id() && "unexpected base"); |
| unsigned idx_id = use->GetSingleWordInOperand(kAccessChainIndex0InIdx); |
| Instruction* idx_inst = context()->get_def_use_mgr()->GetDef(idx_id); |
| if (idx_inst->opcode() != SpvOpConstant) { |
| seen_non_const_ac = true; |
| return false; |
| } |
| unsigned value = idx_inst->GetSingleWordInOperand(kConstantValueInIdx); |
| if (value > max) max = value; |
| return true; |
| }); |
| return seen_non_const_ac ? original_max : max; |
| } |
| |
| void EliminateDeadInputComponentsPass::ChangeArrayLength(Instruction& arr_var, |
| unsigned length) { |
| analysis::TypeManager* type_mgr = context()->get_type_mgr(); |
| analysis::ConstantManager* const_mgr = context()->get_constant_mgr(); |
| analysis::DefUseManager* def_use_mgr = context()->get_def_use_mgr(); |
| analysis::Pointer* ptr_type = |
| type_mgr->GetType(arr_var.type_id())->AsPointer(); |
| const analysis::Array* arr_ty = ptr_type->pointee_type()->AsArray(); |
| assert(arr_ty && "expecting array type"); |
| uint32_t length_id = const_mgr->GetUIntConst(length); |
| analysis::Array new_arr_ty(arr_ty->element_type(), |
| arr_ty->GetConstantLengthInfo(length_id, length)); |
| analysis::Type* reg_new_arr_ty = type_mgr->GetRegisteredType(&new_arr_ty); |
| analysis::Pointer new_ptr_ty(reg_new_arr_ty, SpvStorageClassInput); |
| analysis::Type* reg_new_ptr_ty = type_mgr->GetRegisteredType(&new_ptr_ty); |
| uint32_t new_ptr_ty_id = type_mgr->GetTypeInstruction(reg_new_ptr_ty); |
| arr_var.SetResultType(new_ptr_ty_id); |
| def_use_mgr->AnalyzeInstUse(&arr_var); |
| // Move arr_var after its new type to preserve order |
| USE_ASSERT(arr_var.GetSingleWordInOperand(kVariableStorageClassInIdx) != |
| SpvStorageClassFunction && |
| "cannot move Function variable"); |
| Instruction* new_ptr_ty_inst = def_use_mgr->GetDef(new_ptr_ty_id); |
| arr_var.RemoveFromList(); |
| arr_var.InsertAfter(new_ptr_ty_inst); |
| } |
| |
| void EliminateDeadInputComponentsPass::ChangeStructLength( |
| Instruction& struct_var, unsigned length) { |
| analysis::TypeManager* type_mgr = context()->get_type_mgr(); |
| analysis::Pointer* ptr_type = |
| type_mgr->GetType(struct_var.type_id())->AsPointer(); |
| const analysis::Struct* struct_ty = ptr_type->pointee_type()->AsStruct(); |
| assert(struct_ty && "expecting struct type"); |
| const auto orig_elt_types = struct_ty->element_types(); |
| std::vector<const analysis::Type*> new_elt_types; |
| for (unsigned u = 0; u < length; ++u) |
| new_elt_types.push_back(orig_elt_types[u]); |
| analysis::Struct new_struct_ty(new_elt_types); |
| analysis::Type* reg_new_struct_ty = |
| type_mgr->GetRegisteredType(&new_struct_ty); |
| uint32_t new_struct_ty_id = type_mgr->GetTypeInstruction(reg_new_struct_ty); |
| uint32_t old_struct_ty_id = type_mgr->GetTypeInstruction(struct_ty); |
| analysis::DecorationManager* deco_mgr = context()->get_decoration_mgr(); |
| deco_mgr->CloneDecorations(old_struct_ty_id, new_struct_ty_id); |
| analysis::Pointer new_ptr_ty(reg_new_struct_ty, SpvStorageClassInput); |
| analysis::Type* reg_new_ptr_ty = type_mgr->GetRegisteredType(&new_ptr_ty); |
| uint32_t new_ptr_ty_id = type_mgr->GetTypeInstruction(reg_new_ptr_ty); |
| struct_var.SetResultType(new_ptr_ty_id); |
| analysis::DefUseManager* def_use_mgr = context()->get_def_use_mgr(); |
| def_use_mgr->AnalyzeInstUse(&struct_var); |
| // Move struct_var after its new type to preserve order |
| USE_ASSERT(struct_var.GetSingleWordInOperand(kVariableStorageClassInIdx) != |
| SpvStorageClassFunction && |
| "cannot move Function variable"); |
| Instruction* new_ptr_ty_inst = def_use_mgr->GetDef(new_ptr_ty_id); |
| struct_var.RemoveFromList(); |
| struct_var.InsertAfter(new_ptr_ty_inst); |
| } |
| |
| } // namespace opt |
| } // namespace spvtools |